1. Field of the Invention
The present invention relates to a security system for preventing trespassing of an unauthorized person, vehicle, animal, or the like upon a specific region, and more particularly, to a security system which is more effectively operated in the case where the specific region or a site is monitored by a daughter or remote station of a so-called remote monitoring system.
2. Description of the Prior Art
The security system so far known is such a one as will, upon its sensor's sensing foreign matter, give an alarm at the locality by a siren or the like. With the development of the industrial television system, however, another system has also come to be used that will take, by means of a television camera, images of the state of affairs at the site and transmit the images taken to a monitoring site where the camera images are to be monitored by means of a monitoring television.
But there are some problems in the above described television monitoring system. That is, a system for transmitting such images needs a larger frequency band width, and if the monitoring site is remote from the site to be monitored by several hundred meters or more, special equipment and means for transmission becomes, in general, necessary. Therefore, the system becomes considerably expensive, or, in some cases, even becomes impracticable from the point of view of the means for transmission.